Hinge structure for foldable display terminal

ABSTRACT

A hinge structure for a foldable display terminal is provided. The hinge structure for a foldable display terminal having a flexible display panel installed therein is foldable inward and outward in a fully unfolded state such that the flexible display panel is disposed inside and outside and a screen on which an image such as a moving image is displayed is invisibly disposed inside or visibly disposed outside in a state in which the foldable display terminal is folded.

TECHNICAL FIELD

The invention relates to a hinge structure for a foldable displayterminal that is foldable in two opposite directions and, moreparticularly, to a hinge structure for a foldable display terminal thatis foldable in two opposite directions in which the hinge structure fora foldable display terminal having a flexible display panel installedtherein is foldable inward and outward in a fully unfolded state and ascreen on which an image such as a moving image is displayed isinvisibly disposed inside or visibly disposed outside in a state inwhich the foldable display terminal is folded.

BACKGROUND ART

Foldable display terminals are configured to perform various functions.Examples of the functions include a data and speech communicationfunction, a function of capturing a still image or a moving image usinga camera, a speech storing function, a function of reproducing a musicfile using a speaker system, and a function of displaying a still imageor a moving image (a video).

Some foldable display terminals have additional functions for playinggames, and some foldable display terminals are embodied as multimediadevices. Recent foldable display terminals can also receive broadcast ormulticast signals and reproduce a video or a television program.

Researches for supporting and improving other functions of foldabledisplay terminals in addition to the above-mentioned functions have beencarried out. These researches include modification and improvement ofstructural constituents of the foldable display terminals and additionand improvement of software or hardware.

In general, a display module of a foldable display terminal displaysinformation which is processed by the foldable display terminal. Forexample, when the foldable display terminal is in a call mode, thedisplay module displays a user interface (UI) or a graphic userinterface (GUI) associated with a call.

When the foldable display terminal is in a video call mode or an imagecapturing mode, the display module displays a captured or/and receivedimage, a UI, or a GUI. The display module includes a liquid crystaldisplay, a thin-film transistor liquid crystal display, an organic lightemitting diode, a flexible display, or a 3D display.

A flexible display (or a flexible LCD) has been regularly researchedwith its merit of deformability. It takes much time to use a rolleddisplay like a paper roll as shown in science-fiction movie.

Therefore, transitional forms of flexible displays will be many useduntil the flexible displays are regularly used with sufficientdevelopment thereof, and these transitional forms will be similar tocurrent structures of communication terminals.

Accordingly, there is necessity for description of usage and protectionof flexible displays when such flexible displays are used in foldabledisplay terminals.

An example of such a hinge structure for a foldable display terminalhaving a flexible display panel installed therein is disclosed in KoreanPatent Application Laid-open No. 10-2015-0096827 (Title of theInvention: HINGE STRUCTURE AND FOLDABLE DISPLAY DEVICE INCLUDING THESAME).

SUMMARY OF THE INVENTION Technical Problem

An objective of the invention is to provide a hinge structure for afoldable display terminal that is foldable in two opposite directions inwhich the hinge structure for the foldable display terminal having aflexible display panel installed therein is foldable inward and outwardin a fully unfolded state and a screen on which an image such as amoving image is displayed is invisibly disposed inside or visiblydisposed outside in a state in which the display terminal is folded.

Solution to Problem

In order to achieve the above-mentioned objective, there is provided ahinge structure for a foldable display terminal that is foldable in twoopposite directions, the hinge structure including: upper panels (10)and lower panels (30) that are provided on right and left sides of acentral joint (40) and that are foldable inward and outward with respectto the central joint (40); and upper joints (41, 42) that are providedon the right and left sides of a top of the central joint (40) and thatare connected to the upper panels (10) and connected to each other.

The hinge structure further includes lower joints (34) that are providedon the right and left sides of a bottom of the central joint (40) andthat are connected to lower sliders (32).

The two upper panels (10) may be rotatably connected to the centraljoint (40),

Two tilting elastic modules may be provided on each of the right andleft sides of the central joint (40), and an upper slider (12) may beconnected to the two tilting elastic module.

A push member (84) having a rotatable rotational member (50) installedtherein may be provided in the push member (84).

The push member (84) may be slidably inserted into a sliding rail of anopen groove of the upper slider (12) and an elastic force may be appliedthereto in a direction in which the push member is compressed by anelastic member (49).

A range in which the push member (84) is able to move in the slidingrail (31) may be limited depending on a length of a guide groove (86).

The rotational member (50) that is rotatably provided in the push member(84) may be rotatably connected to a connecting portion (9) of bottomsurfaces of the upper panels (10) and is rotatably connected to thelower slider (32).

The connecting portion (9) fixed to the bottom surfaces of the upperpanels (10) may be connected to the rotational member (50) and anelastic force may be applied to the upper panels (10) in two oppositedirections with respect to the central joint (40) when the upper panels(10) are being folded or unfolded.

A cover portion (76) may be provided such that exposed end faces of thecentral joint (40), the upper joints (41, 42), and the lower joints (34)are covered.

The central joint (40) may include a four-axis gear in which a pair ofrotational bars (44) and two gears (45) engaging with the rotationalbars (44) are coupled to each other,

The pair of rotational bars (44) engaging with each other may beconfigured to rotate simultaneously in two opposite directions.

An elastic drive member including a front rod (62), a shaft (64) that isinserted into the front rod (62), an elastic member (49) such as a coilspring that is fitted onto the shaft (64), and a rear rod (66) intowhich the shaft (64) is inserted may be provided on two opposite sidesof the rotational bar (44).

Advantageous Effects of the Invention

With the hinge structure for a foldable display terminal that isfoldable in two opposite directions according to the invention, thehinge structure for a foldable display terminal having a flexibledisplay panel installed therein is configured to be foldable inward andoutward in a fully unfolded state and a screen on which an image such asa moving image is displayed is invisibly located inside or visiblylocated outside in a state in which the foldable display terminal isfolded.

According to the invention, the support portion of the first upper jointis provided to come into contact with the surface of the central jointin a state in which the upper panels and the lower panels coupled to theupper panels are fully unfolded. A part of the flexible display panelattached onto the first upper joint is prevented from being recessedinward when it is pressed by a user. Accordingly, it is possible toprevent the part of the flexible display panel from being damaged.

Since the tilting elastic module is provided in the central joint, auser can stop unfolding of the flexible display panel by adjusting anangle by which the flexible display panel is unfolded, and the flexibledisplay panel can be semi-automatically unfolded when the flexibledisplay panel is unfolded over a predetermined range.

While the upper panels are being unfolded or folded, an elastic forcecan be normally applied to the upper panels and the lower panels outwardfrom the central joint and the flexible display panel coupled to theupper panels can be normally tightly stretched.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention.

FIG. 2 is a perspective view illustrating a bottom of the hingestructure for a foldable display terminal illustrated in FIG. 1 .

FIG. 3 is a perspective view illustrating a state in which an upperhinge portion and a lower hinge portion connected to a central joint areseparated from each other in the hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention.

FIG. 4 is an enlarged perspective view illustrating a part of jointportions of the lower hinge portion illustrated in FIG. 3 .

FIG. 5 is an exploded perspective view illustrating a state in whichsome constituent parts of the upper hinge portion and the lower hingeportion illustrated in FIG. 3 are separated.

FIG. 6 is an exploded perspective view illustrating a state in whichconstituent parts of the bottom of the upper hinge portion are separatedin the hinge structure for a foldable display terminal that is foldablein two opposite directions according to the invention.

FIG. 7 is an exploded perspective view illustrating a state in which aright upper panel of the upper hinge portion is separated from thecentral joint in the hinge structure for a foldable display terminalthat is foldable in two opposite directions according to the invention.

FIG. 8 is a perspective view illustrating the bottom of the upper hingeportion in the hinge structure for a foldable display terminal that isfoldable in two opposite directions according to the invention.

FIG. 9 is an exploded perspective view illustrating a connectionstructure of upper sliders which are connected to the central joint andslide in the upper panel in the hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention.

FIG. 10 is an exploded perspective view illustrating a state in which asemi-automatic drive portion is coupled to the upper slider connected tothe central joint in the hinge structure for a foldable display terminalthat is foldable in two opposite directions according to the invention.

FIG. 11 is a perspective view of a drive module that connects a pair ofupper panels, semi-automatically drives the upper panels, and applies anelastic force outward from the central joint when the upper panelsrotate in the hinge structure for a foldable display terminal that isfoldable in two opposite directions according to the invention.

FIG. 12 is a perspective view of the drive module in a state in whichthe drive module illustrated in FIG. 11 is folded outward with respectto the central joint.

FIG. 13 is a diagram illustrating movement of a rotational member whilea pair of upper sliders connected to the central joint is being foldedoutward from a state in which the upper sliders are folded inward in thehinge structure for a foldable display terminal that is foldable in twoopposite directions according to the invention.

FIG. 14 is a sectional view illustrating movement of front rods on twosides of the central joint to which an elastic force is applied by aspring when the front rods move along a tilt stopper while the hingestructure for a foldable display terminal that is foldable in twoopposite directions according to the invention is being unfolded from astate in which it is folded in an in-folding manner.

FIG. 15 is a sectional view illustrating movement of the front rods ontwo sides of the central joint to which an elastic force is applied by aspring when the front rods move along the tilt stopper while the hingestructure for a foldable display terminal that is foldable in twoopposite directions according to the invention is being folded in anout-folding manner in FIG. 14 .

FIG. 16 is a sectional view illustrating a state in which the lowersliders and the upper sliders are connected to each other by rotationalmembers in the hinge structure for a foldable display terminal that isfoldable in two opposite directions according to the invention.

FIG. 17 is a perspective view illustrating a state in which one lowerslider is separated from the central joint in FIG. 16 .

FIG. 18 is a perspective view illustrating a state in which the lowersliders are connected to the central joint by rotational members in thehinge structure for a foldable display terminal that is foldable in twoopposite directions according to the invention.

FIG. 19 is a perspective view illustrating a state in which one lowerslider is separated from the central joint in FIG. 18 .

FIG. 20 is a perspective view illustrating a configuration in which alower slider and a rotational member are connected in the hingestructure for a foldable display terminal that is foldable in twoopposite directions according to the invention.

FIG. 21 is a perspective view and a sectional view illustrating a statein which a connecting member is coupled to the lower slider in FIG. 20 .

FIG. 22 is a perspective view illustrating a disassembled state and anassembled state of a tilting elastic module which is provided in thecentral joint in the hinge structure for a foldable display terminalthat is foldable in two opposite directions according to the invention.

FIG. 23 is a perspective view illustrating an assembled state of a coverportion which is provided on a side surface of a connecting part of apair of lower panels according to the invention.

FIG. 24 is an exploded perspective view illustrating a disassembledstate of the cover portion which is provided on a side surface of aconnecting part of a pair of lower panels according to the invention inFIG. 23 .

FIG. 25 is a sectional view illustrating movement of the hinge structurefor a foldable display terminal that is foldable in two oppositedirections according to the invention while the hinge structure is beingfolded in the out-folding manner from the state in which the hingestructure has been folded in the in-folding manner with a flexibledisplay panel installed on the upper panels.

REFERENCE SIGNS LIST

4: Flexible display panel, 7: Attachment member, 9: Upper panelconnecting portion

10: Upper panel, 12: Upper slider, 15: Guide rail

30: Lower panel, 32: Lower slider, 34: Lower joint

36: Guide rail, 40: Central joint, 41: First upper joint

42: Second upper joint, 44: Rotational bar, 49: Elastic drive member

50: Rotational member, 60: Guide bar, 62: Front rod

64: Shaft, 66: Rear rod, 70: Tilt stopper

76: Cover portion, 80: Connecting portion, 82: Connecting member

84: Push member, 86: Guide groove, 141: Support portion

EMBODIMENTS OF THE INVENTION

FIG. 1 is a perspective view of a hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention. FIG. 2 is a perspective view of the bottom of the hingestructure for a foldable display terminal illustrated in FIG. 1 .

Referring to FIGS. 1 and 2 , a hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention has a configuration in which upper panels 10 and lower panels30 on the right and left sides of a central joint 40 are foldable inwardand foldable outward.

Upper joints 41 and 42 connected to the upper panels 10 are connected tothe right and left sides of the top of the central joint 40. Lowerjoints 34 connected to lower sliders 32 are connected to the right andleft sides of the bottom of the central joint 40.

FIG. 3 is a perspective view illustrating a state in which an upperhinge portion and a lower hinge portion connected to a central joint areseparated from each other in the hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention. FIG. 4 is an exploded perspective view illustrating a part ofjoint portions of the lower hinge portion illustrated in FIG. 3 .

Referring to FIGS. 3 and 4 , a cover portion 76 is configured such thatexposed end faces of a central joint 40, upper joints 41 and 42, and alower joint 34 are covered to make side surfaces of the central joint40, the upper joints 41 and 42, and the lower joint 34 invisible fromthe outside.

FIG. 5 is an exploded perspective view illustrating a state in whichsome constituent parts of the upper hinge portion and the lower hingeportion illustrated in FIG. 3 are separated.

Referring to FIG. 5 , first upper joints 41 and second upper joints 42which are connected to upper panels 10 are coupled to right and leftsides of the top of the central joint 40, and lower joints 34 which areconnected to a lower panel 30 are coupled to right and left sides of thebottom of the central joint 40.

Each lower joint 34 is connected to a corresponding lower slider 32, andthe lower slider 32 is disposed inside the side surface of thecorresponding lower panel 30.

FIG. 6 is an exploded perspective view illustrating a bottom view inwhich constituent parts of the upper hinge portion are separated in thehinge structure for a foldable display terminal that is foldable in twoopposite directions according to the invention.

Referring to FIG. 6 , a pair of upper panels 10 on the right and leftsides is connected to the central joint 40 such that they can rotate.Two tilting elastic modules (see FIG. 22 ) are provided on the right andleft sides of the central joint 40, and upper sliders 12 are connectedto the tilting elastic modules.

A push member 84 in which a rotatable rotational member 50 is providedis installed in each upper slider 12.

The push member 84 is inserted into a sliding rail of an open groove ofthe upper slider 12 to slide therein, and an elastic force is applied tothe push member 84 in a direction opposite to a compression direction ofa plurality of elastic members 49 such as compression coil springs.

A range in which the push member 84 can move in the sliding rail 31 islimited by a length of a guide groove 86.

The rotational member 50 which is provided to be rotatable in the pushmember 84 is rotatably connected to a connecting portion 9 of the bottomsurface of the upper panel 10 and is rotatably connected to the lowerslider 32.

Accordingly, when the upper panels 10 are being folded or unfolded, anelastic force is applied to a pair of upper panels 10 in tow oppositedirections which are perpendicular to the length direction of thecentral joint 40 with respect to the central joint 40 because theconnecting portions 9 fixed to the bottoms surface of the upper panels10 are connected to the rotational member 50.

FIG. 7 is an exploded perspective view illustrating a state in which theright upper panel of the upper hinge portion is separated from thecentral joint in the hinge structure for a foldable display terminalthat is foldable in two opposite directions according to the invention.

Referring to FIG. 7 , the upper slider 12 that slides on the bottomsurface of the right upper panel 10 out of the upper sliders 12 isseparated from the bottom surface of the upper panel 10.

FIG. 8 is a perspective view illustrating the bottom of the upper hingeportion in the hinge structure for a foldable display terminal that isfoldable in two opposite directions according to the invention.

Referring to FIG. 8 , on the rear surfaces of the upper panels 10according to the invention, the upper sliders 12 on the right and leftsides of the central joint 40 are slidably inserted into the guide rails15 formed in the upper panels 10, and the push member 84 that slidesalong the sliding rail 31 with an elastic force applied by an elasticmember 49 such as a compression coil spring is provided in each upperslider 12.

The connecting portion 9 fixed to the rear surface of each upper panel10 is connected to one guide groove 54 of the rotational member 50 by anattachment member 7 such as a rivet or a screw.

FIG. 9 is an exploded perspective view illustrating a connectionstructure of upper sliders which are connected to the central joint andslide in the upper panel in the hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention. FIG. 10 is an exploded perspective view illustrating a statein which a semi-automatic drive portion is coupled to the upper sliderconnected to the central joint in the hinge structure for a foldabledisplay terminal that is foldable in two opposite directions accordingto the invention.

Referring to FIGS. 9 and 10 , two tilting elastic modules are providedon each side of the central joint 40, and the upper slider 12 isrotatably connected to ends of a guide bar 60 and a rotational bar 44 ofthe tilting elastic module.

A center hole 55 of the rotational member 50 is rotatably connected tothe push member 84 by the attachment member 7 such as a screw or arivet, and the connecting portion 9 provided on the bottom surface ofeach upper panel 10 and a connecting member 82 fixed to thecorresponding lower slider 32 are rotatably connected to guide grooves53 and 54 on two opposite sides of the center hole.

FIG. 11 is a perspective view of a drive module that connects a pair ofupper panels, semi-automatically drives the upper panels, and applies anelastic force outward from the central joint when the upper panelsrotate in the hinge structure for a foldable display terminal that isfoldable in two opposite directions according to the invention.

Referring to FIG. 11 , when the upper sliders 12 are straightlystretched with respect to the central joint 40, the rotational member 50is configured to rotate in a direction parallel to the length directionof the central joint 40.

FIG. 12 is a perspective view of the drive module in a state in whichthe drive module illustrated in FIG. 11 is folded outward with respectto the central joint.

Referring to FIG. 12 , when the upper sliders 12 are folded in the arrowdirection, the guide groove 53 of the rotational member 50 connected tothe connecting member 82 fixed to the corresponding lower slider 32rotates downward.

FIG. 13 is a diagram illustrating movement of the rotational memberwhile a pair of upper sliders connected to the central joint is beingfolded outward from a state in which the upper sliders are folded inwardin the hinge structure for a foldable display terminal that is foldablein two opposite directions according to the invention.

Referring to FIG. 13 , FIG. 13(a) illustrates a state in which the uppersliders 12 are folded in an in-folding direction (the arrow direction).The guide groove 53 of the rotational member 50 connected to theconnecting member 82 fixed to the corresponding lower slider 32 rotatestoward the central joint 40 about a rotation axis.

FIG. 13(b) illustrates the upper slider 12 and the central joint 40 in astate in which a pair of upper panels 10 is fully unfolded, and FIG.13(c) illustrates the position of the rotational member 50 in a state inwhich the pair of upper panels 10 are folded in an out-folding direction(the arrow direction) which is opposite to that in FIG. 13(a).

Each upper panel 10 is connected to the guide groove 54 and is suppliedwith an elastic force from the elastic members 49.

Each lower panel 30 is connected to the guide groove 53 and is suppliedwith an elastic force from the elastic members 49.

The elastic members 49 apply an elastic force to the push member 84. Thesame elastic force from the elastic members is applied to the rotationalmember 50 provided in the push member 84 such that the rotation axis 55can rotate. The same elastic force from the elastic members 49 isapplied to the push member 84 and the upper panel 10 and the lowerslider 32 connected to the guide grooves 53 and 54. Accordingly, thepair of upper panels 10 and the pair of lower sliders 32 are normallysupplied with an elastic force such that they are pressed in theopposite directions perpendicular to the length direction of the centraljoint 40.

FIG. 14 is a sectional view illustrating movement of front rods on twosides of the central joint to which an elastic force is applied by aspring when the front rods move along a tilt stopper while the hingestructure for a foldable display terminal that is foldable in twoopposite directions according to the invention is being unfolded from astate in which it is folded in an in-folding manner. FIG. 15 is asectional view illustrating movement of the front rods on two sides ofthe central joint to which an elastic force is applied by a spring whenthe front rods move along the tilt stopper while the hinge structure fora foldable display terminal that is foldable in two opposite directionsaccording to the invention is being folded in an out-folding manner inFIG. 14 .

FIGS. 14 and 15 illustrate movement of the tilting elastic module (seeFIG. 22 ) while the upper panels 10 and the lower panels 30 coupled tothe upper panels 10 are simultaneously unfolded to a fully unfoldedstate from a state in which the flexible display panel is disposedinside with a pair of upper panels 10 folded (an in-folded stateillustrated in FIG. 14(a)).

Referring to FIG. 14(c), support portions 141 of the first upper joints41 are configured to come into contact with the surface of the centraljoint 40 in a state (a state illustrated FIG. 14(c)) in which the upperpanels 10 and the lower panels 30 coupled to the upper panels 10 arefully unfolded.

Parts of the flexible display panel attached onto the first upper joints41 are prevented from being recessed inward when the parts are pressedby a user. Accordingly, it is possible to prevent the parts of theflexible display panel from being damaged.

When the pair of upper panels 10 is unfolded from the in-folded state(see FIG. 14(a)), an elastic force is applied to the front rods 62 fromthe elastic members 49 such as springs fitted onto the shafts 64, andthe front rods 62 with the elastic force applied thereto are hooked tothe tilt stopper 70 formed on a part of the central joint 40 andsemi-automatically press the upper panels 10 and the lower panels 30coupled to the upper panels 10 such that they are fully unfolded ormovement of the upper panels 10 and the lower panels 30 coupled to theupper panels 10 stops at a specific position.

FIG. 16 is a sectional view illustrating a state in which the lowersliders and the upper sliders are connected to each other by rotationalmembers in the hinge structure for a foldable display terminal that isfoldable in two opposite directions according to the invention. FIG. 17is a perspective view illustrating a state in which one lower slider isseparated from the central joint in FIG. 16 .

Referring to FIGS. 16 and 17 , a connecting portion 80 of each lowerslider is provided in the hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention. A front part of the connecting member 82 fixed to theconnecting portion 80 is coupled to the guide groove 53 of therotational member 50 by an attachment member 7 such as a screw or arivet, and the rotation axis 55 of the rotational member 50 is rotatablyconnected to the push member 84 provided in the corresponding upperslider 12.

The connecting portion 9 formed on the bottom surface of the upper panel10 is coupled to the other guide groove 54. The lower panels 30 areplaced on the bottom surfaces of the lower sliders 32. The lower panels30 are coupled to the corresponding upper panels 10 by the attachmentmember 7 such as a screw or a rivet.

Each lower slider 32 is inserted into a guide rail 36 formed on theinner side surface of the corresponding upper panel 10 in a state inwhich the lower slider is coupled to the upper panel 10, and slidesalong the guide rail 36.

FIG. 18 is a perspective view illustrating a state in which the lowersliders are connected to the central joint by rotational members in thehinge structure for a foldable display terminal that is foldable in twoopposite directions according to the invention. FIG. 19 is a perspectiveview illustrating a state in which one lower slider is separated fromthe central joint in FIG. 18 .

FIGS. 18 and 19 illustrate a state in which the lower panel 30 and theupper slider 12 are removed in the configuration illustrated in FIGS. 16and 17 .

FIG. 20 is a perspective view illustrating a configuration in which alower slider and a rotational member are connected in the hingestructure for a foldable display terminal that is foldable in twoopposite directions according to the invention. FIG. 21 is a perspectiveview and a sectional view illustrating a state in which a connectingmember is coupled to the lower slider in FIG. 20 .

Referring to FIGS. 20 and 21 , the front part of the connecting portion80 of the lower slider 32 is inserted into a front hole of theconnecting member 82 and a rear part thereof is coupled to the rear partof the connecting member 82 by the attachment member 7 such as a rivetor a screw.

FIG. 22 is a perspective view illustrating a disassembled state and anassembled state of a tilting elastic module which is provided in thecentral joint in the hinge structure for a foldable display terminalthat is foldable in two opposite directions according to the invention.

The tilting elastic module which is provided in the central joint 40will be described below with reference to FIG. 22 . The central joint 40includes a four-axis gear in which a pair of rotational bars 44 and twogears 45 engaging with the rotational bars 44 are coupled to each other.

The pair of rotational bars 44 engaging with each other is configured torotate simultaneously in the two opposite directions.

An elastic drive member including a front rod 62, shafts 64 that areinserted into the front rod 62, elastic members 49 such as coil springsthat are fitted onto the shafts 64, and a rear rod 66 into which theshafts 64 are inserted is provided on two opposite sides of eachrotational bar 44.

The front rod 62 of the elastic drive member is configured to slidealong the shafts 64 onto which the elastic members 49 such as coilsprings are fitted. The front rod 62 is interposed between the guide bar60 and the rotational bar 44 and slides to move forward and rearward.

A tilt stopper 70 is formed at a position at which the front rod 62 isprovided in the central joint 40. A semi-automatic drive member thatautomatically moves the tilting elastic module including the rotationalbar 44, the guide bars 60, and the front rode 62 with an elastic forcewhen the elastic drive member reaches a threshold point at the time ofrotation about the central joint 40.

The shape of the tilt stopper 70 can be freely deformed to adjust anangle by which the front rod 62 is tilted.

FIG. 23 is a perspective view illustrating an assembled state of a coverportion which is provided on a side surface of a connecting part of apair of lower panels according to the invention. FIG. 25 is a sectionalview illustrating movement of the hinge structure for a foldable displayterminal that is foldable in two opposite directions according to theinvention while the hinge structure is being folded in the out-foldingmanner from the state in which the hinge structure has been folded inthe in-folding manner with a flexible display panel installed on theupper panels.

Referring to FIGS. 23 and 24 , a cover portion 76 is provided at aposition at which a pair of lower panels 30 is connected to each othersuch that the central joint 40 and the upper and lower joints areinvisible from the outside.

FIG. 25 is a sectional view illustrating movement of the hinge structurefor a foldable display terminal that is foldable in two oppositedirections according to the invention while the hinge structure is beingfolded in the out-folding manner from the state in which the hingestructure has been folded in the in-folding manner with a flexibledisplay panel installed on the upper panels.

Referring to FIG. 25 , a flexible display panel 4 is provided on theupper panels 10 in the hinge structure for a foldable display terminalthat is foldable in two opposite directions according to the invention.

Movement of the hinge structure according to the invention while thehinge structure is gradually being unfolded (states illustrated in FIGS.25(b) and 25(c)) from a state (a state illustrated in FIG. 25(a)) inwhich the hinge structure has been folded in an in-folding manner inwhich the flexible display panel 4 is disposed inside and then is beingfolded in an out-folding manner in which the flexible display panel 4 isdisposed outside is illustrated in FIG. 25 along with movement of thecover portion 76.

INDUSTRIAL APPLICABILITY

While an exemplary embodiment of the invention has been described aboveusing specific terms, such description is only for explanation and it isobvious that the embodiment can be modified in various forms withoutdeparting from the technical spirit and scope of the appended claims.Such modified embodiments should not be understood separately from thespirit and scope of the invention and should belong to the appendedclaims.

1. A hinge structure for foldable display terminal, the hinge structurecomprising: Each upper panels (10) are provided on right and left sidesof a central joint (40) and that are foldable with respect to thecentral joint (40); wherein the two upper panels (10) are rotatablyconnected to the central joint (40), wherein elastic modules areprovided on each of the right and left sides of the central joint (40),2. The hinge structure for foldable display terminal according to claim1, wherein an upper slider (12) is connected to the elastic module,wherein a push member (84) having a rotatable rotational member (50)installed therein is provided in the push member (84), wherein the pushmember (84) is slidably inserted into a sliding rail of an open grooveof the upper slider (12) and an elastic force is applied thereto in adirection in which the push member is compressed by an elastic member(49).
 3. The hinge structure for foldable display terminal according toclaim 1, wherein a rotational member (50) that is rotatably provided inthe push member (84), and wherein an elastic force is applied to theupper panels (10) in two opposite directions with respect to the centraljoint (40) when the upper panels (10) are being folded or unfolded. 4.The hinge structure for foldable display terminal according to claim 1,wherein upper joints (41, 42) that are provided on the right and leftsides of a top of the central joint (40) and that are connected to theupper panels (10) and connected to each other.
 5. The hinge structurefor foldable display terminal according to claim 1, wherein the centraljoint (40) includes a four-axis gear in which rotational bars (44) andgears (45) engaging with the rotational bars (44) are coupled to eachother, wherein the rotational bars (44) engaging with each other isconfigured to rotate simultaneously in two opposite directions, andwherein an elastic drive member including a front rod (62), a shaft (64)that is inserted into the front rod (62), an elastic member (49) such asa coil spring that is fitted onto the shaft (64), and a rear rod (66)into which the shaft (64) is inserted is provided on two opposite sidesof the rotational bar (44).
 6. The hinge structure for foldable displayterminal according to claim 1, wherein a range in which the push member(84) is able to move in the sliding rail (31) is limited depending on alength of a guide groove (86).